Hydrocarbons, such as oil and gas, are commonly obtained from subterranean formations that may be located onshore or offshore. The development of subterranean operations and the processes involved in removing hydrocarbons from a subterranean formation typically involve a number of different steps such as, for example, drilling a borehole at a desired well site, treating the borehole to optimize production of hydrocarbons, and performing the necessary steps to produce and process the hydrocarbons from the subterranean formation.
In conventional drilling operations, a drill bit is mounted in a bottom hole assembly (BHA) at the end of a drill string (e.g., drill pipe plus drill collars). At the surface a rotary drive turns the string, including the bit at the bottom of the hole, while drilling fluid (or “mud”) is pumped through the string and returned through an annulus. Various well systems may control borehole pressure of a well during this drilling process. In a conventional open well system, piping/riser for returning drilling fluid is typically open to atmospheric pressure. Closed-loop well systems include surface equipment to which the returning drilling fluid can be diverted.
Certain managed pressure drilling (MPD) systems may be characterized as closed and pressurized drilling fluid systems. MPD and like systems provide various techniques for regulating borehole pressure. However, existing pressure regulation techniques are often inadequate for use on certain types of drilling rigs to drill wells through reservoir formations.